On the histology and function of certain secondary sexual organs in the cuttle fish Doratosepion confusa

Abstract

In 1923 a novel case of sex-dimorphism was described (Massy and Robson (12), p. 435) in the South African cuttle fish, Doratosepion confusa , Smith. The male of this species was shown to possess a long streamer-like prolongation of the lateral fins (called for convenience the “tail”) which is entirely absent in the female. In the latter the fins terminate, as usual, close to the aboral extremity of the body. Another remarkable feature was revealed in the study of this animal. Two strips of tissue (called the “lateral organs”) were found, one on each side towards the extremity of the “tail,” which upon microscopical examination were found to consist largely of an enigmatical substance unlike any of the special tissues characteristic of Cephalopoda. Since the publication of the preliminary account of these structures, they have been histologically examined, and all the data that could be brought to bear upon their interpretation have been assembled.